Electron emitters, or field emitters, generally refer to structures that emit electrons when placed within an appropriate electric field. Typically, prior art electron emitters are formed by depositing layers, or laminates, of a homogeneous conductive material on an insulating material. The deposition of layers onto the insulating material may be done using any of the commonly known methods such as vapor deposition or sputtering of the conductive material. Once the electron emitter is formed, it functions by emitting electrons along an edge that has a geometric discontinuity of small radius of curvature.
When electron emitters are formed by depositing layers of conductive material onto the insulating material, they inherently have several undesirable features. For example, in order to achieve a sharp edge feature of a radius of curvature of a few hundreds of angstroms, the electron emitter layers must be very thin (typically less than 500 angstroms). Due to the thinness of the layers, electron emitters are fragile and must be adequately supported. In addition to being adequately supported, the electron emitters must be exposed to a relatively high electric field which requires a relatively high voltage to generate, for example at least 50 volts.
Accordingly, there exists a need for an electron emitter layer that substantially overcomes these problems.